Figure 5

rCST9 afforded protection against pulmonary tularemia. (A) Balb/c mice (n = 12 mice/group) were given 50 pg of rCST9 i.n. concurrently with LVS (500 CFU/mouse; 100 × LD50s). rCST9-treated/infected mice had significantly higher survival compared with infected mice alone (P< 0.01). Data are presented as mean ± SEM. (B) Parallel groups of mice (n = 6/group) were euthanized 48 h after treatment and/or infection to collect lungs, liver and spleen to determine LVS burden. Bacterial loads in all three organs of rCST9-treated/infected mice were significantly lower compared with infected mice alone (P< 0.01). (C) Ft-infected mice treated with rCST9 showed moderate cellularity and maintained the architecture of the alveolar space similar to uninfected/untreated (normal) controls. LVS-infected mice alone showed a loss of alveolar architecture and hypercellularity. Magnification, 10x.